Heat 2 tbsp oil in a pan add the onions and fry for 10-15 minutes, stirring occasionally until softened and lightly coloured.
Cut the pork into sizeable chunks, then add to the pan and stir over a fairly high heat to seal and brown them all over. Stir in the paprika, cook briefly, then add the stock and bring to the boil.
Cover and cook for 30-35 minutes, until the pork is tender. Stir in the crème fraîche and simmer for a further 2 minutes. (You can prepare the dish to this point up to 2 days ahead or freeze for up to 3 months.) If you have a few chives or a bit of parsley handy, snip this over the pork before serving with rice and a green vegetable – broccoli or stir-fried cabbage make the perfect accompaniment to this simple but delicious dish.